Recently, increasing demands have been placed for anti-wear and anti-seizing material and low-friction material considering that light alloy need to be used and miniaturization is necessary as countermeasures for higher rotation speed, higher compression ratio, weight reduction and fuel consumption improvement for the purpose of enhancing the performance in the internal combustion engine, and extensive studies have heretofore been conducted.
So far, it has been publicly known to form a wear-resistant layer by spray-coating or plating a metal, an oxide or a carbonate onto the sliding portions of the machine parts.
The wear-resistant layer is discussed below exemplifying a piston ring. Most of the conventional surface-treated piston rings are ones obtained by plating chromium or spray-coating of molybdenum onto the outer peripheral surfaces of the steel-base piston ring member.
However, the chromium-plated piston ring exhibits poor seizing resistance relative to the cylinder liner composed of cast iron as an opponent member, and hence seizing and scuffing are liable to take place. In order to improve the above-mentioned drawback, the cylinder liners made of cast iron to which nickel, chromium, molybdenum and/or boron, and niobium are added are used. The above cast iron, however, exhibits poor workability as compared with ordinary cast irons (FC material), and hence presents another disadvantage such as increased manufacturing cost.
The piston ring onto which molybdenum is spray-coated, on the other hand, exhibits good seizing resistance with respect to the cylinder liner composed of cast iron as an opponent member. With the engines which are subjected to the thermal load of higher than 300.degree. C., however, the oxidation of molybdenum imposes problem with regard to adherence property between the piston ring member and the spray-coated layer. Moreover, molybdenum is so expensive that the piston ring eventually becomes expensive.
The present invention is to eliminate the above-mentioned defects inherent in the conventional arts, and its object is to provide a slide member which can be used for forming slide surfaces of piston rings, cylinder liners, slide surfaces of pistons, and slide surfaces of air compressors, and which is less expensive than the molybdenum spray-coated materials, and which exhibits excellent wear resistance and adherence property, and which exhibits superior scuffing resistance to the chromium-plated materials, and which can be used even under high-temperature conditions.